On 4/19/07, Alan B. Pearce <A.B.Pearce@rl.ac.uk> wrote:
> > I am looking for such a device. I need it small, fast, and I need at
> > least three.
> > Output current should be settable, over a reasonable range. I expect
> > to be using 10-100mA. Input is from a 9 - 12V source.
> >
> > Anyone seen something like this?
> > Linear solutions are not acceptable.
>
> The best solution I can think of is to use an LM317 in current mode - total
> of 2 components for a fixed current source, the LM317 and a resistor to set
> the current.
>
> Take the output from the adj terminal, and select the resistor from the
> output to adj terminals for 1.25V drop at the desired current.
>
> To make current settable, use an FET as an adjustable resistor, or use a
> range of resistors to set a range of fixed currents, and switch them in and
> out as desired using FET switches.

Alan, this will be just sourcing, so will need also a swich for
changing the current direction into the load (for sinking).
 As usualy we are planning solutions without full specifications.
David, have mercy and spit the problem entirely... when will be the
satellite launched ?
Will be necessary 10...100mA at -200C in condensed acid atmosphere ?
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